Finding the Third Proportional to 90.50 and 140.31

Step by Step Solution

1. Step 1: Write the proportion equation
   90.50 : 140.31 = 140.31 : x
2. Step 2: Convert to fraction form
   90.50/140.31 = 140.31/x
3. Step 3: Cross multiply
   90.50x = 140.31 × 140.31
4. Step 4: Simplify right side
   90.50x = 19,687.60
5. Step 5: Solve for x
   x = 19,687.60/90.50
6. Step 6: Final answer
   x = 217.54